In order to carry out the wind tunnel test of high speed helicopter coaxial rigid rotor in 3.2 m wind tunnel, CARDC conducted a research on the key technology of separating coaxial rigid rotor wind tunnel. The key technical problems were analyzed, including coaxial rotor transmission, coaxial rotor union, differential pitch control, rotor aerodynamic performance separation measurement and rotor spacing adjustment. ?2 m diameter rotor model wind tunnel test rig, the rotor balance and rotor control system were developed. The rotor coaxial reverse rotation, coaxial rotor union, differential pitch control and rotor lift offset adjustment rotor, rotor aerodynamic performance isolated measurement, rotor spacing adjustment, and other functions were realized. The wind tunnel test verified that the test technology has the advantages of high technology maturity, high accuracy of data repeatability and multiple adjustable parameters.